It is well known to coat food products, such as fruits, vegetables and nuts, to protect them against mold, rot and water damage and to improve their appearance and, hence, their marketability. Common coatings now in use employ proteins, gums, resins, hydrocolloids, waxes, and oils either alone or in combination, to achieve certain desired objectives. Enhancing appearance, slowing moisture loss, affecting the respiration or ripening process of fruits, nuts, and vegetables, are several of the goals of many modern food coatings.
Coating fruit, first with a sorbate and then with a wax, is disclosed by U.S. Pat. No. 4,434,184, granted Feb. 28, 1984 to Paul M. Nelson.
Coating food products with a shellac based coating is disclosed by U.S. Pat. No. 4,810,434, granted Mar. 7, 1989, to Jonathan Seaborne and David C. Igberg.
U.S. Pat. No. 5,554,445, granted Sep. 10, 1996, to Henryk Struszczyk and Olli Kivekäs, discloses encapsulation of seeds by a film of microcrystalline chitosan.
U.S. Pat. No. 5,283,064, granted Feb. 1, 1994, to Tsutomu Suzuki; Kenichi Hashiudo; Takayuki Matsumoto; Toshihiro Higashide and Takeru Fujii discloses making a capsule that is composed of chitosan; U.S. Pat. No. 2,040,880, granted May 19, 1936, to George W. Rigby, discloses making a then film product from deacetylated chitin. U.S. Pat. Nos. 2,040,880, 5,283,064, and 5,554,445 are non-analogize art to the subject invention.
An object of the present invention is to provide a new and improved coating and a method of preparing and using the coating.
Another object of the present invention is to provide a coating composition that is easy to manufacture and apply.
The present invention utilizes atypical properties of chitosan (at biological pH values, chitosan is positively charged) to provide an improved coating film for food products, such as fruits, vegetables and nuts that is easy to apply.